Much of the high quality fiber for the textile industry is provided for by cotton. About 90% of cotton grown worldwide is Gossypium hirsutum L., whereas Gossypium barbadense accounts for about 8%. Consequently, the modification of cotton fibers characteristics to better suit the requirements of the industry is a major effort in breeding by either classical methods or by genetically altering the genome of cotton plants. Goals to be achieved include increased lint fiber length, strength, dyability decreased fuzz fiber production, fiber maturity ratio, immature fiber content, fiber uniformity and micronaire.
WO024585 describes methods and means to modulate fiber quality in fiber-producing plants, such as cotton, by modulating sucrose synthase activity and/or expression in such plants.
U.S. Pat. No. 6,472,588 and WO0117333 provides methods for increasing the quality of cotton fiber produced from a cotton plant by transformation with a DNA encoding sucrose phosphate synthase. The fiber qualities include strength, length, fiber maturity ratio, immature fiber content, fiber uniformity and micronaire.
WO9508914 discloses a fiber producing plant comprising in its genome a heterologous genetic construct. The genetic construct comprises a fiber-specific promoter and a coding sequence encoding a plant peroxidase, such as a cotton peroxidase.
WO9626639 provides methods whereby encoding sequence preferentially directing gene expression in ovary tissue, particularly very early in fruit development, are utilized to express plant growth modifying hormones in cotton ovule tissue. The methods permit the modification of the characteristics of boll set in cotton plants and provide a mechanism for altering fiber quality characteristics such as fiber dimension and strength.
U.S. Pat. No. 5,981,834, U.S. Pat. No. 5,597,718, U.S. Pat. No. 5,620,882, U.S. Pat. No. 5,521,708 and U.S. Pat. No. 5,495,070 all disclose a method for genetically engineering a fiber-producing plant and the identification of cDNA clones useful for identifying fiber genes in cotton. The cDNA clones are useful in developing corresponding genomic clones from fiber producing plants to enable genetic engineering of cotton and other plants using these genes. Coding sequence from these isolated genes are used in sense or antisense orientation to alter the fiber characteristics of transgenic fiber producing plants.
Published US patent applications US2002049999 and US2003074697 both disclose cotton plants of the genus Gossypium with improved cotton fiber characteristics. The cotton plant has an expression cassette containing a gene coding for an enzyme selected from the group consisting of endoxyloglucan transferase, catalase and peroxidase so that the gene is expressed in cotton fiber cells to improve the cotton fiber characteristics.
U.S. Pat. No. 5,880,110 produces cotton fibers with improved fiber characteristics by treatment with brassinosteroids.
WO 01/40250 provides methods for improving cotton fiber quality by modulating transcription factor gene expression.
WO 96/40924 provides novel DNA constructs which may be used as molecular probes or inserted into a plant host to provide for modification of transcription of a DNA sequence of interest during various stages of cotton fiber development. The DNA constructs comprise a cotton fiber transcriptional initiation regulatory region associated with a gene, which is expressed in cotton fiber. Also is novel cotton having a cotton fiber, which has a natural color, introduced by the expression in cotton fiber cell, using such a construct, of pigment genes.
EP0834566 provides a gene which controls the fiber formation mechanism in cotton plant and which can be used for industrially useful improvement.
However, there is still need for alternative methods and means to alter fiber characteristics of fiber-producing plants such as cotton, which may be further combined with any of other methods to alter fiber characteristics. Such a method is described in the embodiments and paragraphs described hereinafter.